<!DOCTYPE html>
<html>
<head>
	<title></title>
	<style type="text/css">
		
		.out {
			width: 100%;
			height: 100px;
			background: red;
		}
		.one{
			background: green;
			float: left;

			width: 20%;
			height:100px;
		}
		#two {
			background: black;
			float: left;
			width: 20%;
			height:100px;
		}

		a{
			/*不支持宽高*/
			display: inline-block;

			background: red;
			height: 100px;
		}
	</style>
</head>
<body>
<div class="out">
	<div class="one">1</div>
	<div id="two">2</div>
	
</div>

<a href="#">safdsfd</a>

</body>
</html>